System for attachment to and lifting of objects from deep water

ABSTRACT

A deep water recovery system comprising a submersible vehicle and associated equipment, including an object attachment tool for attaching to sunken objects, a messenger line and buoy arrangement having an automatic attachment means and a hoisting cable grip which may be guided from the surface to the sunken object along the deployed messenger line for automatic attachment.

United States Patent 1 Wischhoefer et al.

[ 1 Jan.30, 1973 1 SYSTEM FOR ATTACHMENT TO AND LIFTING OF OBJECTS FROM DEEP WATER [75] Inventors: William J. G. Wischhoefer, Fairfax County; William H. llunley, Alexandria, both of Va.

[73] Assignee: The United States of America as represented by the Secretary of the Navy [22] Filed: Aug. 26, 1965 [21] Appl. No.1 483,908

[52] U.S. Cl. ..1l4/50, 114/16 R [51] Int. Cl. .;.....B63c 7/26, 863g 8/40 Field of Search ..114/l6,16.8,16.4, 20,51, 114/16 R, 16.5, 16.7, 16.6, 50; 89/2; 340/7,

[5 6] References Cited UNITED STATES PATENTS 2,014,389 9/1935 Lord ..6l/69 2,446,994 8/1948 Barker 89 /1 X 2,691,939 10/1954 Hintze ..l02/33 2,977,598 4/1961 Broughton ..89/l X 3,018,752 1/1962 Sorrell ..89/l X 3,158,123 11/1964 Froehlich ..ll4/16 2,939,416 6/1960 Calabrese ..1 14/51 Primary ExaminerSamuel Feinberg Assistant Examiner-James M. Hanley Attorney-L. A. Miller, Q. E. Hodges and H. A. David [57] ABSTRACT A deep water recovery system comprising a submersible vehicle and associated equipment, including an object attachment tool for attaching to sunken objects, a messenger line and buoy arrangement having an automatic attachment means and a hoisting cable grip which may be guided from the surface to the sunken object along the deployed messenger line for automatic attachment.

17 Claims, 19 Drawing Figures PATENTEDJANBO lava I 3.713.414

SHEET 1 OF 6 4 FIG. I.

so s4 40 40 F/ INVENTORS WILLIAM J. a. WISCHHOEFER BY WILLIAM H. HUNLEY 30a 34a Y J y I PATENIEDmao I973 SHEET 2 0F 6 ATTYS.

PATENTEDJANSO I975 SHEET 3 [IF 6 I NVENTORS WIL L IA M J. G. WIS CHHOEF E R WIL HUNLEY BY z PATENTEU JAN 30 I975 SHEET 8 [IF 6 INVENTORS WILLIAM J. G. WISCHHOEFER WL MM H HU/VLEY F m F SYSTEM FOR ATTACHMENT TO AND LIFTING OF OBJECTS FROM DEEP WATER The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.

This invention relates to the recovery of sunken objects from deep water and more particularly to a recovery system utilizing improved submersible vehicle means and novel associated equipment.

The recovery of sunken objects such as ships or portions thereof, downed aircraft, military devices and the like from water depths exceeding the limited range of conventional diving and salvage equipment and practice has become increasingly important to those interested in averting future sinkin'gs as well as to those interested in recovering cargoes or the like. When working from surface vessels alone, the ability to make effective contact with and attachment to a submerged object is severely hampered by underwater currents which force excessive weighting of drop cables, surface water conditions, and particularly the inability to accurately locate the object and to position the recovery device with respect to the object. The use of submersible vehicles in salvage has been restricted by the limited grasping, lifting and manipulating capabilities thereof.

A primary object of this invention is the provision of an improved deep water recovery system comprising submersible vehicle means, such as a bathyscaph, and novel associated equipment for use in effecting the recovery of sunken objects of different weight ranges including in one range those objects which can be brought to the surface by the vehicle itself, another range including those objects which can be lifted by a buoyant device brought by the vehicle to the object for attachment thereto, the device being released from the vehicle to independently carry the object to the surface, and still another range including those objects requiring use of the lifting capabilities of a surface vessel.

As another object this invention aims to accomplish the foregoing through the provision ofimproved equipment including novel attachment tool means for effecting connection between a lifting cable and a submerged object to be brought to the surface.

Yet another object is the provision of improved submersible vehicle carried messenger buoy and attachment tool means whereby the vehicle can make attachment of a messenger line to a sunken object and then release the buoy to deploy the messenger line to an assisting surface vessel so that the messenger line may serve to guide a hoisting cable from the surface vehicle for automatic connection to the sunken object, the hoisting cable being of a strength to apply a desired lifting force to the object.

Other objects and advantages of the invention will become apparent from the following detailed description of presently preferred examples thereof when read in conjunction with the accompanying sheets of drawings forming a part of this specification, and in which:

FIG. 1 is a side elevational view of a bathyscaph outfitted in a search condition according to the invention;

FIG. 2 is an elevational view of a bathyscaph in the process of recovering an object which can be lifted by the reserve buoyancy of the bathyscaph;

FIG. 3 is an enlarged elevational view of an attachment tool in the form of explosively actuable tongs;

FIG. 4 is a side elevational view of a bathyscaph outfitted according to this invention for recovering objects which can be lifted by a hoisting buoy;

FIG. 5 is an enlarged elevational view of a hoisting buoy viewed along line 5-5 of FIG. 4;

FIG. 6 is an enlarged elevational view of another attachment tool;

FIG. 7 is a plan view of the tool of FIG. 6;

FIG. 8 is an elevational view of a bathyscaph outfitted with a messenger buoy for use in recovery of objects requiring hoisting capabilities of a surface vessel;

FIG. 9 is an enlarged elevational view of a messenger buoy viewed along line 9-9 of FIG. 8;

FIG. 10 is a side elevational view of another attachment tool;

FIG. 11 is a plan view of the tool of FIG. 10;

FIG. 12 is a fragmentary sectional view of the portion of the tool within circle 12 of FIG. 11;

FIG. 13 is a side elevational view of the tool of FIG. 10 illustrating a different position of use;

FIG. 14 is a fragmentary sectional view illustrating toggled position of a projectile forming part of the tool of FIG. 10;

FIG. 15 is a diagrammatic illustration of a recovery operation;

FIG. 16 is an enlarged elevational view of a cable connector fitting;

FIG. 17 is an enlarged sectional view of a cable connector fitting which cooperates with that of FIG. 16;

FIG. 18 is a side elevational view of another attachment tool; and

FIG. 19 is a plan view of the tool of FIG. 18.

Referring to FIG. I, the reference numeral 10 indicates a submersible vehicle such as bathyscaph which has been outfitted according to the present invention for search and recovery of small sunken objects, in this example small sunken objects being defined as those in a weight range which can be lifted by the buoyancy of the vehicle itself. The bathyscaph 10 comprises a hull 11 containing quantity of a substantially incompressible but lighter than water liquid such as gasoline which tends to give the bathyscaph a substantial positive buoyancy. This buoyancy is overcome by quantities of shot ballast contained in fore and aft shot hoppers l2 and 13 to effect submersion of the vehicle to the depth of a submerged object S to be recovered. Shot may be controllably discharged from the hoppers when it is desired to change the rate of descent or to ascend.

A spherical passenger cabin 15, capable of withstanding pressures at the depth from which recovery is to be accomplished, forms part of the bathyscaph l0 and comprises a viewing port 16' through which operating personnel can observe and direct certain recovery operations described in detail hereinafter. The bathyscaph 10 is provided with an articulated manipulation arm 18 having a suitable grasping claw or implement 18a at the terminal end thereof. The arm 18 may be of any known construction which is operable under severe pressure conditions.

Thus far the bathyscaph is of conventional construction and it will be understood that it may be propelled by electric motor driven propellers or the like (not shown) during search and recovery operations. In accordance with this invention the bathyscaph 10 is further provided with a basket 20 mounted under the hull 11 in a position wherein small scraps of sunken objects, bottom samples and the like may be deposited by operation of the manipulating arm 18. Such scraps and samples may be taken to the surface by the bathyscaph for inspection and study prior to continuance of the recovery operation.

The bathyscaph 10 when outfitted for searching, ad vantageously carries a sonic mark er marker device 22, known as a pinger, which can be deposited adjacent the object S to be recovered. The pinger 22 provides a sonic, homing signal which facilitates return to the object on subsequent trips by the same or other bathyscaphs. The pinger 22 may be conveniently released by deenergization of an electromagnet normally securing it to the hull 11 or other portions of the bathyscaph.

In accordance with the invention, the bathyscaph 10 is further provided with an object attachment tool in the form of grasping and lifting tongs, generally indicated at 25. The tongs 25 are connected by means of a lifting cable 26 of fixed length to the after shot hopper 13 or to the hull 11 near that hopper. During search operations, the tongs are permitted to depend from the lifting cable 26 in a normal lifting position as shown in FIG. 1.

When the bathyscaph 10 is to carry out a recovery operation of an object within the weight range which can be brought to the surface by the bathyscaph itself, the tongs 25 are carried in the claw 18a of the manipulator 18, the cable 26 being stopped off along the hull 11 by suitable clips 28 which release the cable upon predetermined pull of the cable (see FIG. 2). In this condition the manipulator arm 18 is controlled by personnel in the cabin to place the open tongs 25 onto an object S to be recovered. The tongs 25 are then actuated to a closed condition firmly grasping the object S. This is accomplished through the agency of an actuator cable 29 leading from the cabin to the tongs 25, as will be fully described hereinafter, and adapted to pass an electrical impulse for actuating the tongs.

Referring to FIG. 3, the tongs 25 are illustrated as comprising a first curved tong member 30 terminating in a point 30a, and having an upwardly extending arm 31 including an eye in which is received a suitable shackle 32 connecting the tongs 25 to the lifting cable 26. A second curved tong member 34 is pivoted at 35 to member 30 and has an arm 36 extending in spaced parallel relation to arm 31. Disposed between the arms 31, 36 is an explosive actuating device 38 which is adapted to be electrically detonated from the cabin 15 by means-of the cable 29. The actuating device 38 may comprise any suitable explosive means which will drive the arms 31, 36 apart with sufficient force to implant the tong points 30a, 34a inan object S to be recovered. The tong members 30, 34 are preferably provided with flanges or stops 40 to prevent the tongs from penetrating too far and tearing out light structure of the object S.

by compressed spring means 43 which, after firing of the means 38, continuously urge the tong members toward one another so as to eliminate any looseness of grip which might occur with tearing or deformation of the object under lifting stresses.

When an object S is to be recovered through use of the tongs 25, the bathyscaph hovers over the object and the manipulator arm 18 is used to place the tongs on the object. The tongs 25 are then actuated to an object gripping condition as by the explosive device 38. Thereafter, the bathyscaph increases its buoyancy as by discharging shot ballast from the hoppers 12, 13. As the bathyscaph rises, the cable 26 pulls free of the clips 28, allowing the cable to straighten to its lifting position, after which continued rising of the bathyscaph will bring with it the object S grasped in the tongs 25. In the event the object S offers greater resistance than the bathyscaph buoyancy can overcome, the invention contemplates as a safety feature means for either releasing the tongs 25 or for severing connection of the cable 26 to the bathyscaph. Thus, as one example thereof, an explosively actuated cable cutter (not shown) is provided on the cable 26 between the bathyscaph and the tongs 25. The cable cutter can be actuated by electrical control from the cabin 15 via an electric cable (not shown). The construction of explosively actuated cable cutters is known to those skilled in the art to which the invention pertains and need not be further described herein.

Referring now to FIGS. 4 and 5 there is illustrated a recovery vehicle in the form of a bathyscaph 10' of which parts corresponding to those of bathyscaph 10 are given corresponding reference numerals with a prime mark added. The bathyscaph 10' is outfitted according to the invention for recovery of objects the weight of which is greater than can be effectively handled by the bathyscaphs own reserve buoyancy and yet are less than would be desirable to require the lifting capabilities of surface vessels.

To this end, the bathyscaph 10' is outfitted with a recovery buoy 50 comprising a cylindrical tank or pontoon 51 containing a suitable buoyant materiaLThe pontoon 51 has pintles 52 extending from the ends thereof for engagement with suitable support arms 54 extending from the bow of the bathyscaph. The buoy 50 further comprises a shot hopper 5, containing expendable ballast shot which reduces the buoyancy of the buoy 50 to a value permitting normal operation of the bathyscaph 10'. An attachment tool, generally indicated at and described more fully hereinafter, is suspended from the buoy 50 by a hoisting pendant 61 connected to a hoisting bridle 62 which is in turn connected to suitable hoisting eyes 63. The hoisting bridle 62 is normally in a slack condition and is connected to a latch 64 ofa door 65, the latch and door comprising a shot release mechanism.

With the bathyscaph hovering near the object S to be recovered, the manipulating arm 18 is utilized to position the attachment tool on the object. After the tool 60 is attached, the arm 18 is retracted and the bathyscaph backs away as the buoy 50 is released from the arms 54. The released buoy rises with sufficient force that the resisting object acts throughthe hoisting pendant 61 and bridle 62 to actuate the shot release mechanism 65 to spill shot ballast from the hopper 55. The buoy 50 thereupon accelerates upwardly as the slack is removed from the bridle 62, and when slack is used up, the object S is subjected to an initial impetus tending to break it loose frombottom suction or the like. Thereafter, the buoyancy of the buoy 50 suffices to raise the object to the surface.

Alternatively the shot release mechanism of the buoy 50 may be in the form of electromagnetic means actuable from within the bathyscaph 10. This arrangement is advantageous in that the buoy 50 may be ina state of neutral buoyancy and the bathyscaph will not be subjected to a sudden condition of negative, buoyancy when the buoy is released from the arms 54 prior to releasing of the shot ballast to effect hoisting. Such electromagnetic means for releasing shot. ballast are well known to those skilled in the use and construction ofbathyscaphs and need not be further described here.

The buoy 50* is preferably provided with a sonic pinger 67 by means of which the progress of the buoy 50 to the surface may be tracked, and the buoy and object readily located'upon arrival at the surface.

Turning now to FIGS. 6 and 7, theattachmenttool 60 is illustrated as comprising a generally square base plate or attachment pad 70 having a centrally located pad eye 71 for connection to ahoisting cable such as cable 61 of FIGS. 4 and 5. Mounted'gon each of the four corners of the pad 70 is a-stud gun 72 of the explosive propelling-type by means of whichstuds 73 are driven into an object such as S' to secure the tool 60 thereto. The stud guns 72 may be of any suitable construction known to those skilled'in the art to which the invention pertains. Accordingly the guns, per se will not be further described herein. Suffice it to say that the guns 72 may be electrically fired from the cabin 15 through the agency of electric cable means 75 which comprises a separable connector 76 which releases the terminal portion of the cable means when the bathyscaph backs away after connection of the attachment tool to the object S'.

Another embodiment of the invention is illustrated in FIGS. 8 and 9 wherein a bathyscaph 10" is outfitted for use in the recovery of objects S" of a size and weight requiring the lifting assistance ofsurface vessels. Thus, the bathyscaph 10" is outfitted with a messenger buoy 80 comprising a frame 81 having vertical side members 82 spaced at the top by a cylindrical buoyancy member 83 which is preferably formed of a suitable buoyant material such as a syntactic foam plastic material of the glass microsphere containing type having substantially rigid structural qualities. The side members 82 are also spaced by rods 84 and between the lowerends of the side members are journaled a pair of parallel rollers 85 which serve as a line guide for a messenger line 86 wound on a reel 87 within the frame 81. The buoyancy member 83 as a primary function the maintaining of the frame 81 oriented so that the line guide rollers 85 are positioned at the bottom of the frame. The reel 87,

which is preferably itself formed of a rigid buoyant material such as the mentioned syntactic foam plastic, is provided with a central shaft 88 the ends of whichare suitably journalled in the side members 82, and which shaft has a hollow mid-portion in which is conveniently mounted a sonic pinger 90. In addition, the reel 87 is provided with vanes or ribs 91 extending radially from the shaft 88. These ribs act during ascension of the buoy 80 to retard rotation of the reel 87 and. thereby minimize backlash" possibilities.

The messenger buoy 80 is releasably mounted at-the bow of the bathyscaph 10" by suitable arms 94, the buoy having a. positive buoyancy which does not prevent normal operationof the bathyscaph 10". The messenger line 86, which is preferably formed of a lightweight, buoyant material such. apolypropelyne, is connected toamale fitting 95 ofa cable connector at one end of a hoisting pendant 96. The other end of the hoisting p endant is connected to an attachment tool 98 which is adapted to be positioned with respect to a sunken object S" by means of the manipulator arm 18" of the bathyscaph while the latter is hovering over the ebject.

The attachment tool 98 is best illustrated in FIGS. 10-13 and comprises three inclined legs 100 connected together by a common junction member 101 in the manner of a tripod. The legs are suitably braced by members 102 to which are tangentially fixed a circular plate 103 whichserves as a mounting base for a projectile firing gun 105. A suitable hoisting eye is fixed to the junction member 101, and the legs 100 are fitted at their divergent ends with shoes 108' mounted by ball and socket means 109 to the legs as is best' shown in FIG. 12. The shoes are preferably provided with roughened surfaces 1 10 to aid in gripping the surface of an object to be recovered or in gripping the ocean bottom.

The firing gun may be fired by. an electrical signalpassed over a wire means 111 leading to the cabin 15-" of the bathyscaph 10". The projectile comprises a generally triangular, metal piercing blade 115 having a cable 116 pivotally secured near the center thereof, the cable 116 being spirally coiled on a tapered spool.117 forming part of the gun 105. When the tool 98 is standing on a horizontal metal plate P of the object as shown in FIG. 10, the blade 115 is directed downwardly and the cable 116 lies in a recess in theblade. Upon firing of the gun 105, the blade 115 is caused to pass through the plate P unwinding some of the cable 1 16. Tilting of the blade 115 after penetration will prevent withdrawal of the cable 116 by acting in the nature ofa toggle as illustrated in FIG. 14.

Reverting to FIGS. 10, 11 and 13, the tool 98 further comprises a fourth leg 120 extendingfrom the junction member 101 in axial alignment with one of the three legs 100. The fourth leg 120 therefore is disposed atan angle to. the other two legs 100 and cooperates therewith in the manner of a tripod which can rest ona horizontal surface as shown in FIG. 13 in the event it is desirable to fire the blade 115 into a vertically disposed plate P. Of course the leg 120 is preferably provided with a shoe 121 connected to that leg'by a balljoint similar to joint 109.

After the attachment tool 98 has been secured to the object S to be recovered, the bathyscaph 10" backs off and releases the messenger buoy 80. The latter rises to the surface, paying out messenger line 86 as it goes, and is picked up by a waiting surface vessel 130 such as an LSD (Landing Ship Dock) (FIG. If the object S" offers less resistance than the breaking strength of the messenger line, the vessel 130 may use the messenger line directly to haul up the object. In the usual circumstances, however, the messenger line will not be sufficiently strong for this purpose.

Accordingly, and as illustrated in FIG. 15, a stronger hoisting cable 135 may be lowered along the messenger cable, preferably by a second surface vessel 136 such as an AGOR (Oceanographic Research Vessel). The latter conveniently uses a station keeping line 137 to maintain a distance from the vessel 130 which is preferably one fifth the depth from which the object S is to be recovered.

The hoisting cable 135 is attached to a female connector fitting 138 which is adapted to cooperate with the male fitting 95 on the pendant 96 for automatically connecting the cable 135 to the pendant. The cable 135 is advantageously provided with a swivel 139 above the fitting 138 and several guide rings 140 therebetween.

The fittings 95 and 138 are best illustrated in FIGS. 16 and 17 to which reference will now be made. The fitting 95 (FIG. 16) comprises at one end an eye 143 which may be conveniently connected by a shackle 144 to the pendant 96, and at the other end a pointed guide pin 145. The messenger line 86 is suitably fixed in a central bore of the fitting 95 and the latter is coaxial with the axis of the line. The pin 145 projects from a conical surface 146 leading to a cylindrical surface 147 which is interrupted by an annular groove 148. There is thereby defined a shoulder 149 which is preferably slightly undercut or recessed.

The female connector fitting 138 (FIG. 17) comprises an elongated body 155-having a central bore 156 through which the messenger line 86 freely passes. The body is counterbored at the lower end as at 157 to receive the guide pin 145 of the fitting 95, the body terminating in in a shroud or skirt position 155a defining funnel-like guiding surfaces 157a. The upper end of the body 155 presents apertured ears 158 for connection by bridal means 160 to the hoisting cable 135.

The lower end of the body is provided with a plurality, in this case four, of hooks 162 disposed in slots 163 and pivoted to the body by hardened pins 164. The hooks are biased inwardly toward one another by spring urged plungers 165 but are limited in inward movement as by engagement of the upper end portions 162a thereof with the end walls of the slots 163.

As the cable 135 is lowered along the messenger line and fitting 138 engages the fitting 95, the pin 145 enters the counterbore 157 providing guidance for the fitting 138 as the hooks 162 thereof are spread by the conical surface 146, ride over the surface 147, and drop into the groove 148. Thereafter, upward forces on the cable 135 are transmitted to the fitting 95 through the hooks 162 acting on the shoulder 149. The recessed face of the shoulder 149 acts to tighten the grip of the hooks as lifting forces are applied. The vessel 136 may then readily hoist the object S with the cable 135.

An alternative attachment tool 170 is illustrated in FIGS. 18 and 19. The tool 170 comprises tripod arrangement of three legs 172 rigidly jointed at a common point defined by a lifting eye 173. The divergent ends of the legs 172 each have pivotally connected thereto an attachment pad 175 comprising a plurality of electrically actuable stud guns 176. The stud guns, similar to the previously discussed guns 72 serve to fix the pads 175 to an object to be hoisted in a manner which will be evident in the light of the preceding description.

Although the bathyscaph 10 has been described as being attached to the object S by means of tongs 25, the buoy 50 has been described as being attached to the object S by means of attachment tool 60, the bathyscaph 10' has been described as being outfitted to attach the messenger line by means of attachment tool 98, and an additional attachment tool 170 has been described, it will be understood that the tongs and other attachment tools are usable alternatively depending upon the structural characteristics and size of the object to be recovered. Moreover, it will be understood that more than one such attachment device may be I used concurrently.

Obviously many modifications and variations of the present invention are possible in the light of the'above teachings. It is therefore to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.

What is claimed is:

1. Apparatus for use in recovering objects from deep water, said apparatus comprising:

a submersible vehicle capable of sub rnerging and maneuvering to a sunken object;

a manipulating arm mounted on said vehicle and controllable therefrom;

a hoisting buoy releasably mounted on said vehicle;

a hoisting cable depending from said hoisting buoy and having a free end;

an attachment tool connected to said free end of said cable and actuable from said vehicle to connect said cable to an object; and

said manipulating arm being cooperable with said attachment tool to position the latter adjacent an object for attachment thereto.

2. Apparatus as defined in claim 1 and wherein said hoisting buoy comprises:

a body of buoyant material;

a hopper containing expendable ballast for reducing the buoyancy of said buoy to a relatively small positive buoyancy; and

discharge means for releasing said ballast.

3. Apparatus as defined in claim 2 and wherein said discharge means comprises: I

a door having a closed position for retaining said ballast and movable by said ballast to an open position;

a latch for releasably securing said door in said closed position; and

means for actuating said latch to permit said door to open in response to predetermined upward movement of said hoisting buoy after connection thereof to an object by said attachment tool.

4. Apparatus as defined in claim 2 and wherein said discharge means comprises:

electromagnetic means for releasably holding said ballast in said hopper.

5. Apparatus as defined in claim 2 and wherein said attachment tool comprises explosively actuable tongs.

6. Apparatus as defined in claim 2 and wherein said attachment tool comprises:

an attachment pad;

a plurality of explosively actuable stud guns mounted on said pad and operable to drive anchoring studs into an object for securing said pad thereto; and

eye means on said pad for connection to said cable.

7. Apparatus as defined in claim 2 and wherein said attachment tool comprises:

tripod means;

explosive gun means mounted on said tripod means;

a projectile adapted to be fired by said gun means for penetration into an object to be recovered;

flexible means connecting said projectile to said tripod means; and

said projectile comprising a blade having pivotal connection to said flexible means whereby said blade is rotatable to a toggled position'after penetration for securing said tool and cable to said object.

8. Apparatus for use in recovering objects from deep water, said apparatus comprising:

a submersible vehicle capable of submerging and maneuvering to a sunken object;

a manipulating arm mounted on said vehicle and controllable therefrom;

a messenger buoy releasably mounted on said vehicle and including a messenger line reel;

a messenger line wound on said reel and adapted to be paid out upon rising of said messenger buoy;

a pendant cable having a hoist cable connection fitting at one end connected to said messenger line and having a free end;

an attachment tool connected to said free end of said pendant cable and actuable from said vehicle to connect said pendant cable to an object to be recovered; and

said manipulating arm being cooperable with said attachment tool to position the latter with respect to said object for attachment thereto.

9. Apparatus as defined in claim 8 and further comprising a hoist cable having a second connector fitting slideable on said messenger line and cooperable with the first mentioned fitting to connect said hoist cable to said pendant cable.

10. Apparatus as defined in claim 8 and wherein said attachment tool comprises explosively actuable tongs.

11. Apparatus as defined in claim 8 and wherein said attachment tool comprises:

an attachment pad;

a plurality of explosively actuable stud guns mounted on said pad and operable to drive anchoring studs into an object for securing said pad thereto; and

eye means on said pad for connection to said cable.

12. Apparatus as defined in claim 8 and wherein said attachment tool comprises:

tripod means;

explosive gun means mounted on said tripod means;

a projectile adapted to be fired by said gun means for penetration into an object to be recovered; flexible means connecting said projectile to said tripod means; and said projectile comprising a blade having pivotal con- 5 nection to said flexible means whereby said blade rotatable to a toggled position after penetration for securing said tool and cable to said object. 13. Apparatus as defined in claim 12 and wherein: said tripod means comprises first, second and third legs projecting from a junction member;

said apparatus further comprising a fourth leg projecting from said junction member and in axial alignment with one of said first, second and third legs. l5 14. Apparatus as defined in claim 8 and wherein said messenger buoy comprises:

a frame including a pair of spaced vertical end members, a buoyancy member interconnecting the upper portions of said end members, and line guide means disposed between the lower portions members for rotation about a horizontal axis, said reel comprising radially extending rib means for retarding rotation in water.

15. Apparatus as defined in claim 14 and wherein said reel is formed of a syntactic plastic foam material.

16. Apparatus as defined in claim 8 and wherein said hoist cable connection fitting comprises:

a first connector member including a guide pin portion extending axially of said line;

an enlarged portion presenting a conical surface tapering outwardly going away from said pin portion and presenting an annular shoulder facing away from said pin portion;

said apparatus further comprising a hoist cable connection fitting comprising a second connector member cooperable with said first connector member to effect connection of a hoist cable with said pendant cable.

17. Apparatus as defined in claim 16 and wherein said second connector member comprises:

a body having an axial bore adapted to slideably receive said messenger line;

said bore having a counter-bore at one end of said body adapted to receive said guide pin;

a plurality of hooks pivoted to said body at said one end thereof and adapted to be spread by said conical surface of said first member and to engage said annular shoulder thereof;

biasing means urging said hooks inwardly toward one another and yieldably resisting said spreading thereof; and

said one end of said body comprising shroud means for said hooks and presenting sloping pin guiding surfaces leading to said counter bore.

LII 

1. Apparatus for use in recovering objects from deep water, said apparatus comprising: a submersible vehicle capable of submerging and maneuvering to a sunken object; a manipulating arm mounted on said vehicle and controllable therefrom; a hoisting buoy releasably mounted on said vehicle; a hoisting cable depending from said hoisting buoy and having a free end; an attachment tool connected to said free end of said cable and actuable from said vehicle to connect said cable to an object; and said manipulating arm being cooperable with said attachment tool to position the latter adjacent an object for attachment thereto.
 1. Apparatus for use in recovering objects from deep water, said apparatus comprising: a submersible vehicle capable of submerging and maneuvering to a sunken object; a manipulating arm mounted on said vehicle and controllable therefrom; a hoisting buoy releasably mounted on said vehicle; a hoisting cable depending from said hoisting buoy and having a free end; an attachment tool connected to said free end of said cable and actuable from said vehicle to connect said cable to an object; and said manipulating arm being cooperable with said attachment tool to position the latter adjacent an object for attachment thereto.
 2. Apparatus as defined in claim 1 and wherein said hoisting buoy comprises: a body of buoyant material; a hopper containing expendable ballast for reducing the buoyancy of said buoy to a relatively small positive buoyancy; and discharge means for releasing said ballast.
 3. Apparatus as defined in claim 2 and wherein said discharge means comprises: a door having a closed position for retaining said ballast and movable by said ballast to an open position; a latch for releasably securing said door in said closed position; and means for actuating said latch to permit said door to open in response to predetermined upward movement of said hoisting buoy after connection thereof to an object by said attachment tool.
 4. Apparatus as defined in claim 2 and wherein said discharge means comprises: electromagnetic means for releasably holding said ballast in said hopper.
 5. Apparatus as defined in claim 2 and wherein said attachment tool comprises explosively actuable tongs.
 6. Apparatus as defined in claim 2 and wherein said attachment tool comprises: an attachment pad; a plurality of explosively actuable stud guns mounted on said pad and operable to drive anchoring studs into an object for securing said pad thereto; and eyE means on said pad for connection to said cable.
 7. Apparatus as defined in claim 2 and wherein said attachment tool comprises: tripod means; explosive gun means mounted on said tripod means; a projectile adapted to be fired by said gun means for penetration into an object to be recovered; flexible means connecting said projectile to said tripod means; and said projectile comprising a blade having pivotal connection to said flexible means whereby said blade is rotatable to a toggled position after penetration for securing said tool and cable to said object.
 8. Apparatus for use in recovering objects from deep water, said apparatus comprising: a submersible vehicle capable of submerging and maneuvering to a sunken object; a manipulating arm mounted on said vehicle and controllable therefrom; a messenger buoy releasably mounted on said vehicle and including a messenger line reel; a messenger line wound on said reel and adapted to be paid out upon rising of said messenger buoy; a pendant cable having a hoist cable connection fitting at one end connected to said messenger line and having a free end; an attachment tool connected to said free end of said pendant cable and actuable from said vehicle to connect said pendant cable to an object to be recovered; and said manipulating arm being cooperable with said attachment tool to position the latter with respect to said object for attachment thereto.
 9. Apparatus as defined in claim 8 and further comprising a hoist cable having a second connector fitting slideable on said messenger line and cooperable with the first mentioned fitting to connect said hoist cable to said pendant cable.
 10. Apparatus as defined in claim 8 and wherein said attachment tool comprises explosively actuable tongs.
 11. Apparatus as defined in claim 8 and wherein said attachment tool comprises: an attachment pad; a plurality of explosively actuable stud guns mounted on said pad and operable to drive anchoring studs into an object for securing said pad thereto; and eye means on said pad for connection to said cable.
 12. Apparatus as defined in claim 8 and wherein said attachment tool comprises: tripod means; explosive gun means mounted on said tripod means; a projectile adapted to be fired by said gun means for penetration into an object to be recovered; flexible means connecting said projectile to said tripod means; and said projectile comprising a blade having pivotal connection to said flexible means whereby said blade is rotatable to a toggled position after penetration for securing said tool and cable to said object.
 13. Apparatus as defined in claim 12 and wherein: said tripod means comprises first, second and third legs projecting from a junction member; said apparatus further comprising a fourth leg projecting from said junction member and in axial alignment with one of said first, second and third legs.
 14. Apparatus as defined in claim 8 and wherein said messenger buoy comprises: a frame including a pair of spaced vertical end members, a buoyancy member interconnecting the upper portions of said end members, and line guide means disposed between the lower portions of said end members, said buoyancy member serving to maintain said frame oriented in water with said guide means positioned at the bottom thereof; and a messenger line reel mounted between said end members for rotation about a horizontal axis, said reel comprising radially extending rib means for retarding rotation in water.
 15. Apparatus as defined in claim 14 and wherein said reel is formed of a syntactic plastic foam material.
 16. Apparatus as defined in claim 8 and wherein said hoist cable connection fitting comprises: a first connector member including a guide pin portion extending axially of said line; an enlarged portion presenting a conical surface tapering outwardly going away from said pin portion and presenting an annular Shoulder facing away from said pin portion; said apparatus further comprising a hoist cable connection fitting comprising a second connector member cooperable with said first connector member to effect connection of a hoist cable with said pendant cable. 